Method of making cutting dies



July 26, 1938. G. F. RYAN METHOD OF MAKING CUTTING DIES Original FiledOct. 31, 1954 4 Sheets-Sheet l July 26, 1938. G. F. RYAN 2,

METHOD OF MAKING CUTTING DIES Original Filed Oct. 51, 1934 4Sheets-Sheet 2 64 Figifi u 4 I o 7 I 62 6 J E i W METHOD OF MAKINGCUTTING DIES Original Filed Oct. 31, 1954 4 Sheets-Sheet 3 Pi m.

26, 1938. RYAN 2,124,676

METHOD OF MAKING CUTTING DIES Original Filed Oct. 51, 1934 4Sheets-Sheet 4 Zhwentor Patented July 26, 1938 UNITED STATES METHOD OFMAKING CUTTING DIES George F. Ryan, Lynn, Mass, assignor to United ShoeMachinery Corporation, Paterson, N. J., a corporation of New Jersey IOriginal application October 31, 1934, Serial No.

Divided and this application October 12, 1935, Serial No. 44,741

3 Claim.

This invention relates to methods of making dies and is hereinillustrated in connection with the manufacture of dies for producingshoe part blanks from sheet material such as leather. The presentapplication is a division of application Serial No. 750,861, filedOctober 31, 1934, in my name. I

In the manufacture of shoes it has heretofore been customary to produceshoe parts, such as vamps or quarters which when assembled form theuppers of shoes, either by machine or by hand. In the machine operationit is ordinarily the practice to make use of a metal die which is forcedthrough sheet material by means of a clicking machine or press, therebyto form a blank. In the hand operation it is customary to make use of ashoe part pattern which is used as a guide for a knife which is runaround the periphery of the pattern to form a blank. The machineoperation is employed in most shoe factories in instances where a run ofshoes of a given style to be produced is reasonably large. Some shoefactories, however, heretofore have found it more economical to use thehand cutting operation thereby avoiding the greater initial cost of diesas compared with patterns. This has been true particularly, for example,in factories which make lines of shoes which are subject to frequentstyle changes or in which for any reason the run of shoes is likely tobe small. The patterns customarily employed in carrying out the handcutting operation, while costing less than corresponding dies for use inclicking machines, nevertheless involve a very substantial portion ofthe expense incurred in the cutting of parts which form the shoe upper.

In view of the foregoing, it is an object of the present invention toprovide an improved method of manufacturing cutting dies which willeffect such economies as to make it feasible to utilize dies inproducing shoe parts even in such cases as those in which the run ofshoes is small, thus further making it possible to eliminate to a largeextent the employment of hand cutting methods.

To this end, and as illustrated, the invention provides a method ofmaking cutting dies which consists in providing a template correspondingto the shape of a blank such as a shoe part to be produced in variousdimensions, utilizing the template as a model in cuttingpantographically from sheet material a plurality of cores of differentsizes and attaching cutting blades tothe cores along the peripheriesthereof to produce a graded series of cutting dies. The cores arepreferably formed from light sheet metal which can be cut out by meansof a pattern grading machine in substantially the same manner as it isnow customary to cut out paper or fiberboard patterns. Preferably, thecutting blade is formed from a comparatively thin untempered metal stripwhich can be bent readily about the periphery of a core and permanentlyattached thereto by a welding process, after which the blade istempered. In carrying out the above method it is to be noted that onlyone tern.- plate or pattern is required in making a set of dies forproducing a series of blanks such as shoe parts of similar shape but ofvarious lengths and widths. The method is further advantageous in thatthe dies produced can readily be assembled with the result that the costof making them is not disproportionately greater than the cost ofproducing patterns for hand cutting operations, thus making it feasibleto utilize cutting dies in a comparatively rapid machine operation eventhough the number of shoe parts to be produced is small.

The invention in these and other aspects will be apparent from thefollowing detailed description when taken in connection with theaccompanying drawings and will be pointed out in the claims.

Fig. 1 is a plan view of one form of cutting die produced by carryingout the method of my invention;

Fig. 2 is a cross-section on an enlarged scale taken along lines IIII ofa portion 'of the die illustrated in Fig. 1;

Fig. 3 is a perspective view of a portion of the cutting blade of thedie of Fig. 1;

Fig. 4 is a plan view of a modified form of die which can be produced bythe method of my invention;

Fig. 5 is a cross-section on an enlarged scale taken along the line V-Vof Fig. 4;

Fig. 6 is a perspective view of an intermediate strip for securing theblade to the core of the die shown in Fig. 4;

Fig. 7 is a perspective view of a portion of the blade forming part ofthe die shown in Fig. 4

Fig. 8 is a plan view of a portion of a pattern grading machine forgrading cores in accordance with my invention;

Fig. 9 is a perspective view showing the operation of the punch informing a core;

Fig. 10 is a perspective view illustrating the operation of shearsiii-forming a template;

Fig, 11 is a plan view of a series of graded cores;

Fig. 12 is a plan view of a core after it has been drilled:

Fig. 13 illustrates a portion of a device for bending a cutting blade;

Fig. 14 illustrates a device for producing size nicks in a cuttingblade;

Fig. 15 is a perspective view of an apparatus for bending a blade abouta core and temporarily securing the blade thereto;

Fig. 16 illustrates the manner of permanently securing the blade to thecore by welding; and

Fig. 17 illustrates the step of welding together the ends of a cuttingblade.

As shown in Fig. 1, one form of die 8 produced by my novel methodcomprises a sheet metal core l shaped to correspond in outline to thatof a shoe part blank such as a quarter to be produced by the die, andhaving secured thereto a double-edged blade l2. The blade i2 is formedof a thin strip or ribbon of rolled or milled annealed steel stockwhich, as shown in Fig. 3, has flanges I 4 projecting laterally from thecentral portions thereof and spaced apart by the thickness of the coreI0. The stock is bent along the periphery of the core and permanentlysecured thereto with its body portion normal to the faces of the core byspot-welding the flanges to the faces, thus forming a rigid constructionespecially adapted to prevent distortion of the blade by forces actinglaterally thereof. The edge portions of the blade are beveled to produceoppositely disposed cutting edges l6 which the .lie in parallel planesthus constituting cutting members shaped respectively to produce leftand right blanks of corresponding outlines. This construction makes itpossible to utilize a single die for cutting right and left blanks for agiven shoe part, thereby reducing the cost of equipment, as well ascontributing to efliciency in the cutting operation by reducing thenumber of dies to be handled.

To provide for the marking of sizes upon the cutting blanks the cuttingblade i2 is nicked or crimped along its cutting edge as indicated byreference character la.

The die is also provided with prick markers or stabs for the purpose ofindicating the relation of certain portions of the blank to other partsof the shoe in which it is to be assembled. To

. this end, the die is provided with stabs 20, each of which comprises afrusto-conical shank 22 adapted to be inserted in a perforation in thecore i0 and two flanges 24 adapted to engage opposite faces of the coreand having projecting therefrom points or markers 26. Each stab issecured in position in the core by upsetting the material surroundingthe shank to form a shoulder 2! which engages and holds thefrustoconical shank.

Means is provided for stripping cut blanks from the die. As illustratedin Figs. 1 and 2 this means comprises a plurality of stripping membersin the form of rubber plugs 28 located in openings 30 in the core. Thebody portion 32 of each of the plugs 28 is substantially cylindrical andis slit midway of its ends as indicated at 33 so that when the plug isforced into an opening 30 the material of the core surrounding theopening enters the split portion 33 of the plug. This constructionprovides adequate means for supporting the plugs and maintaining them inposition without the use of any additional parts and facilitates theirassembly in the die. Each plug is so shaped that its end portions extendslightly beyond the planes of the cutting edges i6 on opposite sides ofthe core ID with the result that in the operation of the die upon sheetmaterial the end portions of the plugs are forced toward the core duringthe application of pres- I plugs sure but when the pressure -is releasedthe plugs will return to their normal shape, thus forcing out a .cutblank from the interior of the die. During location of the die upon thework the 26 support the cutting edges adjacent to the work above thesame thus reducing likelihood of marring the surface of the work.Further.to assist the operator in removing blanks from the die there isprovided a circular opening 34 through which the operator may thrust afinger in grasping a blank. The opening 34 may also be used tofacilitate picking up the die without touching the cutting edges.

In Figs. 4 and there is illustrated a modifled form of die 35 comprisinga core 36, a cutting blade 38,-extending along the periphery of the coreand preferably welded to an intermediate strip 40 which is in turnwelded to the core. The blade in this instance is preferably' composedof annealed steel stock in the form of a thin ribbon as shown in Fig. 7,and having cutting edges 39. The intermediate strip 40 (Fig. 6) ispreferably of thin sheet metal having lugs 42 formed integrallytherewith and extending from opposite margins of the intermediate strip.These lugs are bent inwardly and are arranged to engage opposite facesof the core along the periphery thereof. By welding the blade 38 to thestrip 40 and then welding the lugs 42 to the core 36 a rigid dieconstruction is produced in that the cutting blade is rigidly andpermanently secured to the core at frequent intervals along itsperiphery, the lugs serving to prevent distortion of the blade laterallyand operating to maintain the blade in substantially perpendicularrelation to the faces of the core.

The die is supplied with marking devices in the form of nicks 46 andwith stabs 46. The stabs 48, which are somewhat different inconstruction from the stabs 20, comprise two conical members 50 havingflanges 5| in engagement with opposite faces of the core 36. One of theflanges has a projection 52 adapted to be forced into a sleeve 54 in,the other portion and positioned in an opening in the core, thus tosecure the stabs in position in engagement with opposite faces of thecore 36.

In order to facilitate the manufacture of dies of the type abovedescribed, for example, dies corresponding in construction to that ofdie 6 illustrated in Fig. 1, use is made of a pattern grading machine bywhich it is possible to produce cores for dies to be used in making allof the blanks of various lengths and widths for shoe parts to be used inmaking shoes of a given range of sizes. One type of the machine which isadapted for this purpose comprises a frame 56 (Fig. 8) having a table 58upon which may be clamped a sheet of metal 60 from which cores such ascore 62 are to be cut. The machine comprises a cutter head 64 carrying areciprocating cutting tool or punch 66 (see Figs. 8 and 9) arranged tocooperate with a die 68 and mounted for movement pantographically withrespect to a model or template l0 clamped to a fixed portion "of theframe, movement of the cutter head being controlled by means of a modeltracing element 14 through linkages I6 and 18 whereby the relative sizeand shape of a core produced bears a predetermined relation to the sizeand shape of the template. For a more complete description of a machinewhich is adapted for this purpose reference may be had to United StatesLetters Patent No. 1,079,022, granted Nov.

18, 1913, upon an application filed in the name' of C. E. Reed.

In making cores for dies for use in producing the necessary blanks for arange of sizes of shoes such as cores 88 (Fig. 11) it is only necessaryfor a shoe manufacturer to supply a. paper pattern of model size,commonly size 43. From this pattern is made a template such as templateI8 (Fig. 10), for example, by outlining the paper pattern upon a sheetof metal 82, trimming to the marked outline, conveniently by means ofshears such as shears 84, and then finishing the edges of the blankformed to correspond accurately to the outline of the paper pattern byfiling them down to size. The template thus formed can then be used in apattern grading machine of the type mentioned to produce from a sheet ofmetal 88 the required number of cores of each of the various sizes.This, of course, requires adjustment of the pantographic levers of themachine in a manner which is well understood in the art of patterngrading. In this way any required number of cores of a series of corescorresponding to blanks of different lengths and widths may be produced.Fig. 11 illustrates the relation between the cases of a series of coresfor dies for producing quarter blanks of one style.

Assuming that a core or cores have been made, the steps for producing adie of the construction shown in'Fig. 1 will now be set forth. The nextoperation performed upon a core such as core I8 (Fig. 12) comprises thedrilling therein of holes 88 for the reception of the stripper plugs 28,openings for the stabs 28 and the finger hole 34.

The core is then ready to have a cutting blade attached thereto. This ispreferably done by bending the blade I2 along the periphery of the corein such manner that the flanges I4 on the blade overlap oppositemarginal edge portions of the core and molecularly uniting the materialof the blade and core preferably by spot-welding the flanges to thecore. This can be conveniently accomplished by apparatus such as thatillustrated in Fig. 15 which comprises a table 86 provided with a stud88 and a pivoted roller 88 which are movable along the table indirections at right angles to each other. A core such as the core I8 isplaced upon the table with one of the stripper openings 38 engaged bythe stud 88. A strip of soft steel stock which is to form the cuttingblade I2, and which has flanged portions I4, is brought into engagementwith the edge of the core with the flange portions extending over thefaces of the core, after which the stud 88 is moved toward the roller 88and at the same time the core is rotated about the stud, with the resultthat the blade is forced into close engagement with the edge of thecore. During this operation the blade is properly positioned heightwiseof the core under the guidance of the flanges I4. After a portion of theblade has been bent along the core a welding electrode 82 is broughtinto engagement with the upper flange I 4, thus to weld the blade to thecore. This operation is continued until the blade has been bent aroundthe entire periphery of the core. At the corners, it is sometimesnecessary to file away or otherwise remove part of the material of theflanges in order that the core may be bent sharply. In bending cornersuse is made of apparatus, as shown in Fig. 13, whereby the blade I2 isclamped by two members 84 and 88 against a third member 88 while a plateI88 is moved into a direction to force the free end of theblade into aposition at an angle to the clamped portion of the blade. This bendingoperation can readily be performed while the blade is partially bentaround the core and secured thereto at one or more points.

After temporarily securing the blade to the core at several points alongthe periphery thereof and after severing ends of the blade stock so thatthey can come approximately together, a second welding operation isperformed permanently to attach the flanges of the blade to the core.This is accomplished, as shown in Fig. 16. by apparatus including twoelectrodes I82, arranged to engage the flanges I4 upon opposite faces ofthe core and to weld the flanges to the core. This welding operation isrepeated along the entire periphery of the core, preferably at pointswhich, as indicated at I84, Figs. 1 and 16, are spaced about one-eighthof aninch apart, thus firmly to secure the blade to the core.

In order to join the free ends of the blade so that the blade will becontinuous about the entire periphery of the die it has been foundexpedient to weld the ends of the blade by the use of a separate pieceof blade stock to flll the gap between the ends of the blade. To thisend a piece of material in the shape of a triangular prism I86 (Fig.17), is inserted in a V-shaped notch formed at the ends of the blade bya three-cornered file. The die is held in position by clamps I II whichengage opposite faces of the core I8 and a welding electrode H8 isbrought into engagement with the material I 86 to weld it in position.After this, the rough edges of the piece I88 are filed or ground down toconform to the shape of the adjacent portions of the blade I2, thusforming a cutting blade having continuous cutting edges.

The size nicks I8 are then formed in the blade by apparatus such asthatshown in Fig. 14, and which comprises a support I88 having slots I88 andH2 large enough to receive the core I8. Upon the support on oppositesides of the slot I88 are U-shaped anvil members I cooperable withprojections II6 on a reciprocable tool I I8 to produce U-shaped nicks inthe edge portions of the blade I2. V-shaped nicks can be formed in theblade by anvil members I28 similarly arranged with relation to the slotH2 and which cooperate with a V-shaped projection I22 on a tool I24.

After the various operations above set forth have been completed the dieis heated and quenched either in oil or air to harden the cutting edges,is sand blasted, painted, size markings are stamped thereon, and stabsand stripper plugs are inserted in the core thus completing the die.

The die -35 illustrated in Figs. 4 and 5 is formed by a method similarto that employed in producing the die 8 illustrated in Figs. 1 and 2except that the strip 48 is usually first welded to the blade 38 and theblade and strip are then bent along the periphery of the core 86 afterwhich the lugs 42 are spot-welded to opposite faces of the core. It isto be understood, however, that my invention also contemplates firstwelding the lugs to the core and then welding the blade to the strip aswell as the alternate method of bending an unattached strip and bladealong the core and simultaneously welding the blade to the strip and thelugs to the core.

In the use of the dies above described such a die is placed upon sheetmaterial in a press with one o! the cutting edges, for example, thelowermost cutting edge I! of the die as shown in Fig. 2, slightly spacedfrom the material by the plugs ll. The presser member of the machine isthen brought down upon the uppermost cutting edge to force the diethrough the material to produce a "left" blank, which is stripped fromthe die by the plugs II upon removal of the pressure. To produce a"right blank the die is merely reversed and the operation repeated.

Having described my invention, what I claim as new and desire to secureby Letters Patent 01' the United States is:

1. The method oi producing dies which consists in providing a templatecorresponding in shape and dimensions to one blank of a series of blanksof similar shape but of diflferent sizes to be cut from sheet material,utilizing the template in cutting pantographically from sheet metal aseries of cores corresponding to the series s,1s4,o7s

of blanks, and attaching cutting blades to the cores to form a gradedseries of cutting dies.

2. The method of producing dies which consists in forming a templatecorresponding in shape to a shoe part blank 01' model size,utilizing'the template as a guide in cutting from sheet metal aplurality of cores corresponding pantographically to a series oi" shoeparts or various lengths and widths to be produced, and welding cuttingblades along the peripheries of the cores to form a graded series ofcutting dies.

3. The method of producing cutting dies which consists in cutting fromsheet metal a core corresponding in outline to a blank to be produced,providing a blade having spaced laterally extending projections, bendingthe blade along the edges of the core while utilizing the projections asguides in locating the blade heightwise of the core, and welding theprojections to the faces of the core.

GEORGE F. RYAN.

